Chinese Anti-Submarine Warfare: Aviation Platforms, Strategy, and Doctrine
Image Credit: Chinese Internet

Chinese Anti-Submarine Warfare: Aviation Platforms, Strategy, and Doctrine


This is the second piece in a two part article evaluating the anti-submarine warfare (ASW) capabilities of the Chinese People’s Liberation Army Navy (PLAN). The first piece documented the PLAN’s significant recent growth in capable ASW surface combatants, with many of those warships equipped with capable organic ASW sensor suites including variable depth sonar (VDS) and towed array sonar systems (TASS). Frigates (FFGs) and destroyers (DDGs) also have organic ASW weapons, such as vertically launched missile/rocket launched torpedo systems.

This piece will consider the rotary and fixed wing ASW capabilities the PLAN currently has and their trajectory, as well as briefly describing some of the other specialized ASW assets that the PLAN is developing. Finally, all of the aforementioned systems and platforms will be brought together to consider what an overall PLAN ASW strategy may look like.

ASW Helicopters

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ASW helicopters greatly expand a warship’s surveillance and engagement area and range against subsurface targets. ASW helicopters are typically equipped with a number of sensors such as surface search radars, sonobuoy launchers, dipping sonar, electro-optic cameras, and the ability to carry torpedoes. Datalinks between the helicopter and warship help to coordinate ASW activities between to optimally prosecute a target.

Therefore it is desirable for an ASW helicopter to have a large payload capacity (both for onboard sensors and weapons) and long range and endurance, all while being small enough to be accommodated aboard a surface combatant’s helipad and hangar. Contemporary ASW helicopters around the world tend to congregate in the 10 ton weight class, such as the very successful SH-60 and MH-60R variants or the European NH-90. Other helicopter types such as the U.K. Merlin family and the Canadian CH-148 Cyclone reside in the 13 ton class, benefiting with greater payload, range, and endurance at the cost of requiring a larger helipad and hangar than 10 ton counterparts.

The PLAN’s ASW helicopter fleet is made up of two main types; the 4 ton Z-9 family derived from the French Panther helicopter, and the larger 12 ton Ka-28 family. Neither type is fully optimal for the PLAN’s ASW efforts in the long term. Z-9 variants can be produced entirely domestically with newer variants featuring more modern sensors; however, the small size of the platform itself limits payload, range, and endurance. The Ka-28 family is larger, but is an imported product from Russia and cannot be easily upgraded with new indigenous sensors and weapons as they are developed. A small number of 13 ton Z-18F ASW helicopters are also in service, and is likely the most capable ASW helicopter the PLAN has today, featuring a large size to accommodate modern sensors and weapons while retaining range and payload, all in a platform that China is capable of producing indigenously. However, the size of the Z-18F means it cannot be fielded aboard any Chinese surface combatants, including the 055 DDG, and instead will likely be limited to operating from carriers and amphibious assault ships.

In the medium term, it has been rumored that the PLAN will develop a navalized, ASW variant of the new Z-20 helicopter, a reverse engineered and improved variant of the UH-60 Blackhawk. A hypothetical “Z-20F” would likely feature similar dimensions and performance to the SH-60/MH-60R, but with a modern Chinese sensor and weapons suite. However, it will be a number of years until such a platform is developed, let alone enters service in meaningful numbers. It is also not known if existing warships designed for Z-9 and Ka-28 sized helicopters will also be able to safely accommodate the Z-20. Until then, Chinese surface combatants will continue to rely on Z-9s and Ka-28s, and while those types are imperfect for the ASW mission, the capability they offer warships is certainly superior to having no ASW helicopter.

Fixed Wing ASW Aircraft

Compared to ASW helicopters, the sensors on ASW maritime patrol aircraft (MPA) are more powerful and sometimes more comprehensive in nature, such as including magnetic anomaly detectors and a more robust electronic support measures (ESM) suite. Fixed wing MPAs tend to be larger compared to ASW helicopters, providing not only longer range, endurance, speed, and payload, but also space for more operator consoles to allow the aircraft to conduct more complex missions independently.

Many MPAs are derived from existing aircraft such as commercial airliners or transporters. The P-3 Orion was derived originally from the L-188 turboprop airliner, and the more recent P-8 Poseidon is derived from the Boeing 737NG airliner. Until recently, the Chinese aerospace industry lacked an appropriate aircraft that could modified into an MPA, and a historical inability of PLA combat aviation to credibly contest air superiority meant the PLAN likely did not consider MPA procurement to be a high priority.

Since 2015, the PLAN has inducted a number of MPAs derived from the Y-9 turboprop tactical transporter designated as KQ-200, or (confusingly) Y-8Q or Y-8GX6. The KQ-200 is fitted with a sensor and weapons suite consistent with other contemporary MPAs. While the aircraft has often been compared with the turboprop P-3, the KQ-200 and the Y-9 airframe it is derived from is substantially heavier than the P-3, with a maximum take-off weight approaching that of the P-8. Furthermore, comparisons with the P-3 may cause one to conclude KQ-200’s sensors and other subsystems are only comparable to the P-3 when they are likely to be more modern (at least compared to P-3 variants without recent upgrades). For the sake of comparison, the closest international peer to the KQ-200 would have been the proposed SC-130J Sea Hercules, a MPA derived from the C-130J airframe similar to Y-9.

At time of writing, it is estimated that at least eight KQ-200s are in service in the PLAN; however, it is likely that many more will be procured. Considering the complexity and the scale of the undersea foe China faces in regional waters, as well as the risk of attrition during wartime, a low end estimate for total number required may be about 30 aircraft, with a high end estimate of 90 or more. It is likely that KQ-200s will eventually be evenly divided between the three naval theater commands.

SURTASS and Other Niche ASW Assets

A number of other niche support systems for the ASW mission have been developed. One such system is the so-called Sino-SOSUS, named referring to the similarity to the U.S.-NATO system of fixed undersea hydrophones designed to track Soviet submarines. The exact location and scale of the Chinese system is not known and is likely a closely guarded secret. However, the fact that such a system is even known to exist is significant in and of itself.

Recently a new class of twin hull surveillance ship has been identified, with a similar size and configuration to the U.S. Navy’s Impeccable class, which is designed to deploy a large and capable “surveillance towed array sensor system” (SURTASS). The Chinese ship has sometimes been referred to as Type 927 (though that designation has also been used to refer to the new training ship in service), with three vessels launched up to date. Six ships of another, smaller type are also currently in service.

Very few navies operate a robust fleet of SURTASS vessels. Such ships are intended for peacetime monitoring of a large expanse of water, rather than operating directly in support of a combat element during anything greater than a low intensity conflict. Simplistically, SURTASS ships can be thought of as a peacetime force multiplier for combat units engaged in ASW such as surface combatants, helicopters, MPAs, and even other submarines, by providing oceanographic and sonar data gathered during peacetime. The pursuit of a number of large, capable SURTASS ships is among the most credible indicators of the PLAN’s seriousness in tackling the ASW mission.

 The PLAN ASW Strategy

The PLAN’s ASW strategy can be viewed in a similar way as the PLAN’s overall naval strategy, by dividing missions as either “regional” or “blue water.” It may be simpler to consider the blue water ASW strategy first, as this will most closely resemble the mission profiles of other international navies. Taskforces of ships including surface combatants, power projection ships (aircraft carriers and amphibious assault ships), and submarines, will operate in waters around the world to defend Chinese interests. The ASW mission for these formations will require surface combatants, onboard ASW helicopters, and submarines to operate together to defend against undersea threats. The lack of overseas air basing means it is unlikely that these taskforces can benefit from MPA support, and SURTASS ships may only occasionally be deployed beyond China’s regional waters. In other words, the ASW strategy for blue water missions will likely seek to defend the naval ships from underwater threats using only blue water capable surface combatants (i.e. frigates and larger ships), helicopters and associated subsystems organic to the ships themselves.

The U.S. Navy fields a very capable nuclear attack submarine fleet in the western Pacific, and Japan has one of the most advanced diesel submarine fleets as well. Other regional navies such as South Korea and Vietnam also have burgeoning diesel submarine capabilities. Therefore, the PLAN’s regional ASW strategy will likely be more complex, because the scale of the threat is also more daunting. This regional strategy will bring together the totality of all PLAN ASW assets, including ASW corvettes, FFGs, DDGs and the ASW helicopters aboard them, as well as diesel electric and nuclear submarines, all of which will in turn be supported by land-based ASW MPAs, fixed underwater hydrophone arrays, and data collected from SURTASS ships patrolling the region.

In peacetime, Chinese regional ASW will likely seek to monitor waters close to China in the littorals and including the first island chain, and identify and track underwater activity. During wartime, an additional step in the mission will include targeting and eliminating hostile submarines as well, with the goal of neutralizing underwater threats to Chinese ports (both naval and civilian) and Chinese surface ships operating in the region. Defending a fixed area of water will require surface combatants and ASW MPAs to conduct patrols alongside each other, possibly further coordinated by fixed underwater hydrophones operating in an early warning role, to detect and engage targets of opportunity.

Minimizing gaps in coverage within a fixed body of water will require not only qualitatively capable sensors and systems operated by well trained sailors and airmen, but also a sufficiently large number of assets on station over time and area. It becomes very quickly evident that such an ASW strategy is dependent on the ability to contest the air and naval surface domains, preferably attaining air superiority and sea control, to allow ASW ships and aircraft conduct their missions unmolested. Therefore, the PLAN’s choice to not pursue a robust and comprehensive ASW capability until recently becomes sensible and logical, because in past decades the PLA lacked the capability to even contest the air and naval domain in its regional waters. In such a conflict scenario, ASW assets would either be unable to operate safely or would be outright targeted and destroyed. Conversely, now that the PLAN is pursuing a robust ASW capability across multiple domains and multiple platforms, these systems suggest the PLA views its prospects to contest air superiority and sea control in its periphery as significantly improved.

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